docs: def sample(self, count=5, fields=None, sampling=None, use_cache=True, dialect=None,
               billing_tier=None):
      """Retrieves a sampling of rows for the query.
  
      Args:
        count: an optional count of rows to retrieve which is used if a specific
            sampling is not specified (default 5).
        fields: the list of fields to sample (default None implies all).
        sampling: an optional sampling strategy to apply to the table.
        use_cache: whether to use cached results or not (default True).
        dialect : {'legacy', 'standard'}, default 'legacy'
            'legacy' : Use BigQuery's legacy SQL dialect.
            'standard' : Use BigQuery's standard SQL (beta), which is
            compliant with the SQL 2011 standard.
        billing_tier: Limits the billing tier for this job. Queries that have resource
            usage beyond this tier will fail (without incurring a charge). If unspecified, this
            will be set to your project default. This can also be used to override your
            project-wide default billing tier on a per-query basis.
      Returns:
        A QueryResultsTable containing a sampling of the result set.
      Raises:
        Exception if the query could not be executed or query response was malformed.
      """
      return Query.sampling_query(self._sql, self._context, count=count, fields=fields,
                                  sampling=sampling, udfs=self._udfs,
                                  data_sources=self._data_sources).results(use_cache=use_cache,
                                                                           dialect=dialect,
                                                                           billing_tier=billing_tier)